1. Field of the Invention
The present invention relates to a Patrone and a camera using the Patrone. More particularly, this invention is concerned with a Patrone having a mechanism that disables film, which is stored in the form of a roll in the. Patrone, from being wound in or fed from the Patrone unexpectedly, and a camera using the Patrone.
2. Description of the Related Art
FIG. 21 shows a known conventional Patrone used in general; that is, a Patrone 70 in which photographic film of 35 mm width is wound about an internal spool in roll form.
The Patrone 70 has a cylindrical body 71 whose top and bottom are sealed shut up to intercept light tightly. A film wind spool 72 provided in the Patrone 70 is freely rotatable therein Photographic film of 35 mm width is wound about the spool 72 and stored in the Patrone 70. A film port 71a is formed like a slit on the circumference of the cylindrical body 71 along the center axis of the cylindrical body 71. A leader 73 of the photographic film is shown coming out of the film port 71a. The unexposed photographic film stored in the Patrone 70 is loaded in a camera with the leader 73 pulled out of the film port 71a.
The Patrone 70 does not have a mechanism that when the Patrone 70 exists as a sole unit, locks the internal film. The spool 72 about which the film is wound may therefore rotate unexpectedly to wind the leader into the Patrone 70. After photography, in general, exposed film is rewound into the Patrone 70 and the leader 73 alone is exposed outside the Patrone as it initially is. When the Patrone 70 is demounted from a camera with the leader 73 pulled out of the film port 71a, the leader 73 may be pulled unexpectedly. This causes the exposed film to come out. The photographed film is thus exposed.
In efforts to resolve these drawbacks, various proposals have been made in the past. For example, as disclosed in Japanese Laid-open Patent Application No. 2-114257, a sprocket is placed in a Patrone to form a mechanism for locking film. When film is unused, the sprocket is used to lock a perforation formed on a side edge of the film in the vicinity of a film port. When the film is used, the lock is released so that the film will not be pulled in or out of the Patrone. According to the disclosure in Japanese Laid-open Patent Application No. 2-214854, a fitting hole is bored in the vicinity of a film port in a Patrone. When film is unused, a locking chip is locked in the fitting hole to prevent movement of film. When the film is used, the lock is released so that the film will not be pulled in or out of the Patrone unexpectedly.
A conventional means as that disclosed in the No. 2-114257 or No. 2-214854 publication is locked in a perforation of film or an engagement hole bored in a side edge of film. This causes the film to bear a large load. When the strength of film deteriorates at a cool or cold season, the film may be damaged. Furthermore, since the side edge of film is locked, such a drawback arises that a Patrone becomes large.